Electromagnet.



PATENTBD MAY 5, 1908.

H. ROWNTREE. BLBGTROMAGNBT. l APPLICATION FILED JUNE 23.1905.

NITED sTA'InsATENT OFFICE' 'i HARoLn no'wN'rann, or cnIcAGo, ILLINOIS.,-AssIeNoR To BURDErr-nownrnnn MANU- l FACTURING COMPANY, or CHICAGO,l ILLINOIS, A coRroRATIoN orILLINoIs.

ELEQTROMAGNET.'

Application manine 2a, 1901s.4 smal No. 266,542.

To allwtomit may concern; f' Be It knownthat I, HAROLD RowN'rnnE, a

Chicago,- in thelcount 4of Cooky andvjState of Illinois, have invente a new and useful Electromagnet, @which vthe following is a s pecif ication;

' the core fvvill not .be Weakened'byinduced currents. l

This invention relates to electromagnets.

The object of the invention is to provide an electro magnety wherein the pull exerted on Afurther object vof the `invention is tofpro- Y vide a construction of-electro magnet wherein lquietness of action Without the generation of heat is secured. i

each ot In a more restricted recitation of the obl# ject of the invention, such invention has -for Its object the provision of an electro magnet having a laminated core, the laminations' 'being in o en magnetic `:ircuit With res ect to 'er at one end, and in close magi netic circuit With respect to each other at the other end.

A further 'object of the invention is to rovide an electro magnet in the formofa so enoid, in Which induced deterring Ieffects at thev commencement of the movement of the core thereof are minimized, while a strong induced deterring effect is produced st the comple-l tion of the movement -of suclicore thereby' reducing the current.

A further object of the inven tion'is to provide an electro magnet of thecharacterabove referred to,` wherein windings or coils, into f which the core'enteraare out of circuit atthe YVbeginning of the operation, and are`cut into f circuit at' the end orconivpletion of the Inovement.

A further object of the invent ion is to provide an electro' magnet of the character reierred to, wherein the induced current is accentuated as the solenoid core is drawn into its coils. f

A further obj ect of the invent .on is to pro-v vide an el'ectro.-m'agnet specially designed for use In connection' withA alternating currents.

Other objects 'of i.' the invention-Will apfr pear more fully hereinafter. y

l The invention'c'onsists substantially in the construction, combination, lo'cation'and rela tive arrangement 'of parts all es lWill more fully. appear'llerenafter, as shown 1n the ac- Specication oi Lettersl Patent.

compariyin'gv drawingsandfinally pointed out inthev appended claims'.k

IReferring to the` accompanying l drawings and to the .various views and-'reference signs 4 appearing thereon. igure'l., 1s aview in sec- .t1on of an electro magnet in, the formof a venti'on, Fig. l2, .is`A an endview of` the' fco're 'i vsolenoid embodying? the principles of my in'- j of the solenoid sho'Wn'inFigs 1', and sho\vi ng the solidi end of suchcore, Fig'. '3,"1s aiview.

similar to Fig.: 1, showing the applicationof of ycore em Ellie same referencesign is `used to designate" the same art Whereve kof the partsthereof thatgthe plunger or core another form-of electro-jrnagnetfembodying' y vthe-principles of'my invention.V 5.Fig. 4, isv a. transverse section showing the :construction ployed-lin the magnet showntinl f rit occurs throughout Y y yhave such construction and arrangement 'A Wouldfbe valmost entirely outside vof the coils "or windings at the commencement'of ythe* vsolenoid action,-and almost entirely inclosed"I by such coils or windings' at'the completion yof the solenoid action, so that there Wouldbe `no induced deterrent ee'cts .at the outset,4 and there, would be a strongdeterrent effect reducin the-current yat the end ofthe action or trave of the core. This theoretically'perfeet condition is difficult if not impossibleto attain', in 'practicmformany reasons, with the crdin'ar'5lv construction of solenoid; MoreLv over,-it is lim ortantand:desirable'to avoid the heating e ect yof the current employed in vthey solenoid'- Winding s land also, it' is` desirable to obtain quietness in tthejoperation of"- the electro magnet.- It is also very desir able,= in order to secure economy oi" operatiomthatj; the arnpcrage passingthrough the. solenoid"` kbe 'cut down to the lowest possible point,Y

thereby-y economizinginthe consumption vof `electro magnet. j f

current without weakening the action `of they 1 y `'10Q'A It is among the special ypur oses of `my present invention to accomplisi these andv other results.l 'f' llncarrying out my] invention, therefore, l i y 'propose inra broad statement'of the obiectsvk embodied in the forni ci a. solenoid, te proio'sf and purposes of my invention when eine 1 vide 'means for accentnating or increasing the induced. current as thecore the solenoid is drawn Yint Way, as for instance, the effect increases abnorma core ofthe solenoid is dr coils or windings. -Th poses may be .accomp riety `o dlierent const l0 ments. `While, theref described oneconstru for accomplishing the ob stated, my invention or plunger of o its coils or windings, -or this may be .exp

ressed in anotherl induced retroactive lly as the plunger or aWn further into the ese objects andv purlished in a wide va.- ructions and arrange- I haveshown and ction and arrangement jects andpurpose'sY in its broadest 'not tofbelimited or confined to scope is the s ecific shown and presently to e d e" heretofore encountered in -magnets and solenoids em'- with alternating .cur-

aused by the alteraction of the armature he direction of the cury causing an exceed This diihfcu a solid core since such unbroken pole surface in ly objeclgty would withw e'h the armature may make elicient contact, andthe residu ,1 is sufficient to preven armature at each reversal vthe current.

more kserious objection the special pur, to rovide an e wel as noise or chat accomplishing the my invention, in

combine into one struc features of asolid co chattering, ,and a lam heating `o 'r" 15n`y electro magnet I core made up. of laminat being-preferably', `though inventicns not t softiron-wire, the las magneticgcircn'it w1 vat all-points; exce #where suehfs'ecti'o :closed .magn `may be-,embo whether in asolenmd o electro magnets- I do to belix'nited or restricted lReferrin f shOWniD' .f the magnet igs. 1, and 2,

plungr A1,

- tuwbe'` 1, the coils E, being metallic-lend comprises laminat gather, fand. preferabl e5 Witlrrespect to'each ot er;

. yllilhenasolid cor however, another and an e namely, the heatingfo the core.

oses of my present invention ectro .magnet wherein heat as tering are avoided. In objects and purposes of this respect, .I propose to ture the advantageous re to inat and to that end', :nl the construction propose to' employe 1ons,'the lamination's,-

o belimted or minationsbeing in Q en thresp tirer pt iat not desire,

to 'fthe solen osed withi al magnetism thereofv t therelease of the of1 the direction of.

e is employed, qually, if not encountered, -It is among revent noise or` core 'to prevent in this 'res ect 'my restricted, of

ect to each-d one 'extreme end, united to form a cons trdetion ariety of` ways and 'in other forms of therefore, in this respect.

-oid construc tion t will bessenl that rises a coil inclosing core or n a-"non-metallic held between nonvhe core A1,

' arallel relation greferably I em-y by the pl ploy iron Wire in place of iron plates, thereby rendering the laminations much more per.-

fect. These iron wires Aare assembl mass of cylindrical form and at o the core or plun er, the laminations'or stripsare b razed, wel ed or otherwise formed into an integral' mass or connection, 10r securedw together'as indicated at El, and for onl a" short len 'th as indicated, the indivi ual strands, p a'tes, wires `orlaminations remains ing disconnectedfrom each other throughout t ereinaining portion of the lengththereof. To that end of the' core or lunger where the ends of the `-la'minations tlliereof are disconjnected fromy each other, may be attached 'a l'lever F3,or `other connection through which the action of the 'movements of the plun er orcore may be utilized for operating Switc es or for any other purpose for which the elec-` tro magnet'is adapte If desired, and'in or-r der to concentrate the pull exerted by the solenoid as ,the core thereof approachesl the limit of its movement under the actiqn of the energization of the coils or windings `thereof,

I mount a laminated block G1, over the end. of the solenoid', toward netic end ofthe core moves.

In order to secure the desired abnormal increase o the induced retroactive effect, or to accentuate the actionof the induced current as the lunr or core is drawn into its coils or win ings, in the particular form of eni- .bodiment of this idea a's shown in the drawings, to exem lify the broad rinciples of mvention in t 's respect, suoli ings are preferably wound in multiple coils, bein in .series one with the other. If desire a small s venienfI relation with respect to the solenoid ycore to be operated by@ rodH1 such core, and whichenh into the coils, eventually strikes a ivoted arm J1, lthereby separating contacts 3 7*. This switch is soconn Contact oints K3, K, are closed upon each other, t e lowest section of vthe solenoid vwinding is short circuited, `but as soon' as the switch 1s opened between the contacts KiK* un coils, this sh fore the energizin .the sections of t ne end ofl current passes through all e solenoid Windiililg.- The action of cutting in this .extra co` of the solenoid winding, after the hasbeen drawn into such winding, has not only the effect of cutting down the ani eragc passing through the solenoid to the ex ent of the additiona resistance which is offered by that much additional wire, but it has a very largely enhanced effect in cutting down the amount of amperage owing to the effect produced on the current assing through this additional coil, by its eing4 placed around the plunger or 'core of the solenoid. I have found in practice that a very slight Vaddiwhich the closed mag# mdy colls or win ectedfthat wheri the I y edirito ag4 witch may be placed in cony connected to i0 :more is drawn v lunger or core l tional coil in this'position will very mateaction after the plunger orcore has come in duced currentv becoming accentuated.

contact with the laminated lblock G1. In other words, the induced effect is abnormally increased as the core orv lunger is drawn furi ther into its windings,4 y reason of the in- As above indicated, this result may -be accomplished in a wide variety of different forms of apparatus, and in the broad scope of my invention, therefore, I do not desire tobe lim ited or restricted to the particular form shown.

In Figs. 3, ande, I have shown my invention as embodied in another form of electro magnet, in which is employed a coil F, inclosing a core O, said core being composed of lami- `nations or sections as above described with reference' to the coreor plunger'A. The laminationsorsections composing the core are in similar manner to that above described welded or otherwise formedy into an integral mass or connection at one end therev of, as indicated at P, the individual strands or laminations remaining disconnected from veach other thefremaining portions of the lengths thereof. The ends of the coil F, are held by non-metallic lates R. The welded or otherwise connecte ends of the core is provided with a pole piece S, designed to exert its magnetic influence upon an armature in the performance of the functions of the electro magnet. The electro magnet embodying this construction is designed for use in any 'connection or situation where such use is required or desired. I have indicated an arrangement wherein the pole piece of the mag net exerts its magnetic' influence upon an armature M, carried b a lever L, for operatv ing a contact device I to opener close electric rcircuit between the same and a conduc tor strip H, carried by a su )port G. If de sired, the contact K, may e connected to the lever L, by a s ring W. My invention, however, is not to e limited or restricted in any respects to these details of contact mechanism to be operated by the magnet, the important and valuable feature of which is the provision of a core com rising numerous sections or laminations, pre 'erably sections of round wire, though in this respect the invention is `not to be limited or restricted, such sections being united solidly together, to form the closed magnetic circuit at one end tlu cof, and being disconnected at all points a of *..ransversc sectional area throughout the reniaii'i'ing portion of the length thereof,r

whereby ouietness of operation is attained without heat.

lin the case of the solenoid shownin Figs. l, and t?, the solid brazed, welded or otherwise connected end of the core or plunger is faced smooth in order' to meet the smooth face of the laminated block G1, thereby makinga sufficiently good Contact to prevent fluctua'- tions of current, which might otherwise cause l mechanical vibration. Inany case, whether in the form a solenoid orsome other form. 7o. of electro magnet, the solid welded portion should extend a comparatively limited. dis-fl tance of tlie length of the laminations, as any excess of closed magnetic circuitat lthispoint would `result in the formation `of eddy curf rents, the effect of which would. be to produce considerable heat. t

"From the foregoing description it will be seen that I providey an exceedinglysim le construction of electro magnetwherein t ey go i' core, wljiethelr fixedas in the case of the electro magnet shown in Fig. 3, o r in the form of a plunger for a solenoid asin Fig. I, is lami-A nated in all 4transverse ydirections ,except .aty l one extreme eiidthereofyat'which-erid such rg5- laminations are formed into a closed mag-k netic circuit. n vItwill also ybe ls een that an Q electro magnet embodying the features of f construction describedL mayV be used in any", l situation for operating svvitches, or forother 'purposes wherever desired. i The electro magnet embodying the princi-t ples of my invention is specially designed for use in connection with alternatingcurrent, i' 'i particularly one phase alternating current; 95

n this respect, however, I do not desire to V,be limited or restricted; Having now set forth the objects' and nay ture of my invention, and various forms in which the broad principles thereofmay be 1,00 embodied, I desire it to be understood "that many variations and changes in the details of construction and arrangement might readil occur to persons skilled inthe art and stil fall within the s irit and scope of my invention. I do not esire, therefore., to be limited ror restricted to the exact details shown and described, but Y l What I claim as new and useful and of my own invention and desire to secure by Let- 11o ters Patent is 1. In an electro magnet, for use with alternating currents, said magnet having a core formed of laminations, said laininations being united into a solid mass to form a closed magnetic circuit `at one end, and being disconnected with respect to each other at all other points.

2. An electro magnet, having a core com posed of laminations assembled together in parallel relation, said laminations beingr united in a solid mass atene end of the core, and disconnected from each other at all other points.

3. An alternating current solenoid, havin(y a longer composed of laminations v united so idly together at one end, and disconnected at all other-points.

4.* An electro magnet, for use with alternating currents, said magnet having a core van?? consisting 'of sections of soft iron Wire asseml mounted yadjacent to the4 closed magnetic bled together, and united into an integral l circuit end ofl the core.

' mass at one end of the core, and` disconnected at all other points. v y

5. .electro magnet, for` use with `alternating ,currents, said magnet having a laminated core7 the laminationsf-jof such core being formedl intoa solid mass to form a "closed magnetic circuit Withrespect to each 10 other at one vend, said laminations being in open magnetic circuit at allother points.l

6. ln an alternating current Solenoid, a plunger or core in, combination with coils' or Y windings, Surrounding thel same and so ar- 15 ranged that the induced retroactive effect is abnormally increased as the plunger is drawn into said coils or windings. '2. An alternating current solenoid, having fa core combination with means for in- "fieasing the number of Aturns of wire sur- .,lrounding'the core whereby the induced curv'Trent is accentuated as the core is drawn into 1 the coils.l I f: 9. 8. In an electro magnet, for use with alternating currents, said magnet having a laminated core, the laminations being united into a solidmass to form a closed magnetic'circuit with respect to each other at one end, said i laminations being in open magnetic circuit,

30 at all other points, and amagnetic 9. A solenoid, for use withalternatin curjrents,lsaidfsolnoid having a movable aminated'fcoreor' lunger, the coils or windings of said. solenoldbemg sectional, ,means fory short circuitinga portion of said windings or coils, and means actuated .by the movementI of the solenoid for breaking the short circuit.I

10. In' an alternating 'current solenoid a laminatedcore, the lannnations being solidly vunited into closed.v magnetic circuit relation with respect to Aeach other` at oneend only,`

.anda laminated magnetic mass mounted admass- -jacent tofsaid end.

11. In' an alternating current solenoid, movable core' or plunger, windings or coils,- therefor, said windings or coils being in sec-- tions, a switch normall short circuiting a portion of such coils, an means'acl'.uafted by the movement of the core into theA coils for operating said lswitch to break theshort clrcuit.

In witness whereof, I have hereunto set my hand this 21st day of June, 1905', in the '5.5

presenceV of the' subscribing Witnesses.

`. Witness/es:

r Giras; H. SEEM, ERNEST A. BAUGHMAN.

.HARoLD ROWNTREE.. 1 

